Suction running in vacuum, high side pressure not high, 404a freezer
I have a freezer truck with a Copeland condensing unit (TJAL-030Z-CFV-300) and cold plates inside. It has one TXV for each cold plate. The issue is the suction line quickly runs into a deep vacuum after the compressor starts so the pressure switch does its job and shuts it off. After not finding any leaks, I bypassed the pressure switch for a short test run and it ran fine except for pulling almost 20 inches of vacuum. The high side pressure isn't climbing up like I expected (more familiar with car A/C). The condenser is clean and the fan is working. The pressure in the system isn't equalizing after the compressor is shut off. It does have a CPR valve but when I hook up my gauge before the CPR, it is also in vacuum. So it certainly appears there's a blockage issue. I tried to recover the 404a from the 'king' valve at the compressor, but it just wasn't flowing. At the receiver, it came out nice and fast to my recovery tank and pumped out nicely too (I have an old Promax machine). So it would appear there's a blockage somewhere between the compressor and receiver. That would narrow it down to something internal in the receiver (dip tube maybe?), condenser, or small spun brass brazed-in filter between compressor and condenser. Any easy way to find out where the problem is? Is this a common issue?
I recovered all the refrigerant and it wasn't low or overcharged... but had to recover it from the port on the receiver as it was just trickling out at the compressor, would have probably taken days to get it from there.